19. A part of the monthly expenses of a family isconstant and the rema

1.	19. A part of the monthly expenses of a family isconstant and the remaining varies with the price ofwheat. When the rate ofwheat is Rs. 250 a quintal,the monthly expenses of the family is Rs. 1000and when it is Rs. 240 a quintal, the monthlyexpenses is Rs. 980. Find the monthly expensesofthe family on wheat when the cost of wheat isRs. 350 a quintal,
Answer» Let the constant expenditure be ₹.x Let the consumption of rice by the family be y quintals. x+250y=1000------------------(1) x+240y=980-------------------(2) Subtracting eq (1)and(2) x + 250y =1000 x + 240y = 980 (-) (-) (-) --------------------------- 10y = 20 y= 20/10 y= 2………….(3) Put the value of y in eq 1 x+250y=1000 x + 250(2) = 1000 x+ 500 = 1000 x= 1000-500 x=500………….(4) Total monthly expenditure when the cost of rice ₹350 = constant expenditure + consumption of rice at ₹ 350 per quintal. = x+350y = 500 + 350 × 2 ( From eq 3 & 4) = 500+ 700 = ₹ 1200 Hence, the Total monthly expenditure when the cost of rice ₹350 is ₹ 1200

19. A part of the monthly expenses of a family isconstant and the remaining varies with the price ofwheat. When the rate ofwheat is Rs. 250 a quintal,the monthly expenses of the family is Rs. 1000and when it is Rs. 240 a quintal, the monthlyexpenses is Rs. 980. Find the monthly expensesofthe family on wheat when the cost of wheat isRs. 350 a quintal,

Answer»

Let the constant expenditure be ₹.x

Let the consumption of rice by the family be y quintals.

x+250y=1000------------------(1)

x+240y=980-------------------(2)

Subtracting eq (1)and(2)

x + 250y =1000

x + 240y = 980

(-) (-) (-)

---------------------------

10y = 20

y= 20/10

y= 2………….(3)

Put the value of y in eq 1

x+250y=1000

x + 250(2) = 1000

x+ 500 = 1000

x= 1000-500

x=500………….(4)

Total monthly expenditure when the cost of rice ₹350 = constant expenditure + consumption of rice at ₹ 350 per quintal.

= x+350y

= 500 + 350 × 2

( From eq 3 & 4)

= 500+ 700

= ₹ 1200

Hence, the Total monthly expenditure when the cost of rice ₹350 is ₹ 1200